Oil sender and safety switch



Feb. 21, 1967 J, PALMERONE OIL SENDER AND SAFETY SWITCH Filed April l, 1965 l INVENToR M0552# Pw ,mwa/v5 ATTORNEY5 United States Patent Gtice 3,305,651 OIL SENDER AND SAFETY SWITCH Joseph Palmerone, 705 Ardsley Road, Scarsdale, N.Y. 10583 Filed Apr. 1, 1965, Ser. No. 444,758 2 Claims. (Cl. 2041-83) The present invention relates to lan oil sender and safety switch for engines and, more particularly, a switch of this type adapted to replace the standard oil sender while accomplishing this dual purpose.

As will be appreciated by those skilled in the art, all engines today are provided with oil sender switches to activate an `oil pressure gauge. This gauge, under ordinary circumstances, will operate to indicate or register oil pressures and particularly provide an indication or warning that the engine oil pressure is either approaching or is at a dangerously low value. In far too many instances, human nature will react by either delaying taking action as a result of this warning, completely ignore it or, for that matter, be completely ignorant of the purpose of the warning or the possible consequences. In this connection, a drop in oil pressure can and has resulted in serious damage to engines.

It is, therefore, a principal object of' this invention to provide a device capable of operating as an oil sender switch for activating the oil pressure gauge and to operate as a safety switch for stopping the engine automatically should there be a loss of oil pressure.

Another object is to provide a safety switch for engines operable to automatically shut-ofi the engine ignition system should the oil pressure drop below a predetermined minimum value and, at the same time, serve as a replacement for the standard oil sender switch while also being capable of actuating the oil pressure gauge.

Other objects and advantages will become apparent from the following detailed description which is to be taken in connection with the accompanying drawing illustrating a somewhat preferred embodiment of the invention and in which:

FIG. l is a side elevational view of the engine oil sender and safety switch contemplated by this invention shown associated rather diagrammatically with the engine oil system, ignition system and oil pressure gauge;

FIG. 2 is an enlarged longitudinal sectional view taken along the line 2-2 of FliG. 1;

FIG. 3 is a cross-sectional view taken along the line 3- 3 of FIG. 2; and

FIG. 4 is a sectional view taken along the line 4 4 of FIG. 3.

In the drawings, the oil sender and safety switch of this invention is shown associated with an engine 12 such that it is exposed to the oil pressure system 14, ignition system 16 and oil pressure gauge 18 thereof. The engine 12 may be any one of a number of commercially available engines particularly of the automotive type and the fitting 20, in accordance with the contemplated embodiment of this invention, may be that of the standard oil sender switch of which the present invention most advantageously takes advantage. Under these circumstances, the switch 10 will ybe sensitive to the oil pressure of the system 14 to indicate predetermined low pressure readings on the gauge 18 and actuate the ignition system 16 in the event the oil presure is reduced to a dangerously low value. On the other hand, the switch 10 will operate in response to predetermined and acceptable oil pressure values to permit the ignition system 16 to maintain the engine running while, at the same time, permit the oil pressure gauge to register acceptable oil pressure values.

In performing the dual function, the switch 1t), in accordance with the illustrated embodiment, includes a 3,305,651 Patented Feb. 21, 1967 housing 22 having an interior 24. The housing may be composed of any number of parts which imay be connected in a number of ways; and, as shown, the housing includes an inner end 26 and an outer end 28 together with an interposed partition 30 each of which may be suitably fianged in order to be releasably coupled by means of a number of screws 32. In this connection, a gasket 34 is employed to effect the seal between the housing forward end 28 and partition 30 whereas the outer circumferentially extending periphery of a flexible diaphragn 36 seals the associated annular surface of the inner end 26 and partition 30. This diaphragm also serves to divide the housing interior 24 into an inner oil communicating compartment 38 and outer compartment 40.

The inner end 26 of the housing is provided with a reduced boss 42 as well as a central bore 44 for communicating the chamber 38 with the engine oil and, consequently, the developed oil pressure. The boss will, therefore, serve as an adaptor for mating with the fitting 20 which may take place through the interposed threads 46.

The fiexure or displacement of the diaphragm 36 is transferred to a longitudinally extending shaft 48. Towards this end, the shaft 43 is fixed or otherwise suitably connected to the diaphragm 36. In the illustrated embodiment, this is accomplished by a disk 50 suitably keyed to the shaft 4Sy and sealed relative thereto through the interposed resilient washer 52. A washer 54 disposed on the oil pressure side of the diaphragm 36 is disposed about the central threaded stud 56 which conveniently receives the internally threaded nut 58 which, when threaded tightly upon the stud 56, securely clamps the diaphragm 36 between the disk Si? and washer 54. The other end 6G of the shaft 4S is reduced and is adapted to project through the central opening 62 of the partition 30 as is the case with the adjacent enlarged section of the shaft 48 particularly when the diaphragm 36 is shifted outwardly by means of the oil pressure within compartment 3S The partition 36 is adapted to conveniently mount a stationary contact 64 which is suitably connected to ground. This stationary contact 64 is adapted to cooperate with a movable contact 66 mounted at one end of the arm 63. This arm 63 is pivotally mounted between a pair of upstanding bracket arms '76 and 72, forming part of the partition 3), by the pivot pin 74.

The arm 68 is urged forwardly such that the movable contact 66 engages with the stationary contact 64 by means of the bias of the compression spring 76. The force exerted by means of this spring 76 is adapted to be overcome to thereby open the switch contacts 64 and 66 through the flexure of the diaphragm 36 as a result of engine oil pressure. Under these circumstances, the shaft 48 is shifted rearwardly into engagement with the arm 68 to shift the arm against the bias of the spring 76. With this in tmind, one end of the spring 76 is biased against the shoulder 78 of the arm 68 whereas its other end is biased against the ring 80 of the pin 82. This pin is adapted to project through a central opening in the base 84 of the U-shaped bracket 86, the legs 8S and 90 of which are suitably fixed to the partition 30.

The movable contact 66 has connected thereto an electrical lead 83 the other end of which is connected with a terminal 85 which is electrically connected with the exterior of the housing 22. In this connection, the threaded stud 87 is exteriorly of the housing and conveniently mounts a pair of nuts 94 and 96. These nuts 94 and 96 are adapted to conveniently receive therebetween leads 98 and 100 which may be electrically connected in a suitable fashion to the respective ignition system 16 and oil pressure gauge 18.

To summarize the operation of the switch of this invention, it will initially be assumed that the device is adequately mounted on engine 12 and the oil pressure therein of the system 14 is adequate for the moment to displace the diaphragm 36 sufciently to not cut olf the ignition system 16 or have the oil pressure gauge register an undersirable low oil pressure level. In this regard, acceptable oil pressures will force the diaphragm 36 outwardly and, consequently, shift the shaft 4S into engagement with the arm 68 against the bias of the spring 76 to thereby open the switch contacts 64 4and 66. When engine oil pressure ceases, or is reduced to a danger point, the situation is reected in the retraction of the diaphragm 36. When a predetermined pressure is reached, the switch contacts 64 and 66 will close thereby automatically indicating a warning on the oil pressure gauge 18 and shutting off the engine. In this manner, the present invention effectively prevents any damage to the engine as a result of insucient oil pressure. This value is ascertainable whereby the parameters of the spring and diaphragm and dimensioning of parts are readily within the purview of those skilled in the art.

Thus, the several aforenoted objects and advantages are most eiTectively attained. Although a single somewhat preferred embodiment of the invention has been ldisclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

I claim:

1. An engin-e oil sendel and safety switch comprising in combination:

a housing having a rst and second end and having an interior;

a flexible diaphragm extending across the interior of the housing to divide the housing interior into a rst compartment at the rst end and a second compartment at the second end, said housing being comprised of three parts, the rst part being at the rst en d and the second part being at the second end and a central partition in between both ends extending across the housing interior in said second compartment; Y

the housing first end having an adapter means coupling with the engine and Ian opening communicating with the first compartment receiving engine oil under lpressure iiexing the diaphragm between a irst position at which there is a predetermined lower pressure and a predetermined higher pressure;

a shaft anchored to the center of the diaphragm and extending into the second compartment;

spring means biasing said diaphragm to said first position and adapted to be overcome by a predetermined safe oil pressure whereupon the diaphragm will be disposed in said second position;

a stationary switch contact mounted by said housing in said second compartment;

a movable switch contact coupled for movement with the shaft away from the stationary contact to break an electrical connection therebetween when the diaphragm is in the second position and in contact with the stationary-contact tomake an electrical connection therebetween when the diaphragm is in the first position, the stationary contact extending into the second compartment from said partition and a reciprocal arm being mounted by said partition land mounting the movable contact, a bracket extending from said partition into the second compartment, the spring biasing means including a spring having one end engaged with the bracket and having another end engaged with the arm to urge the arm and, consequently, the movable switch into engagement with the closed contact, said shaft extending through an opening in said partition and engaging the arm when the diaphragm is in said second position to urge the arm against the bias of the spring and, consequently, the movable contact away from the stationary contact.

2. The invention in accordance with claim 1 wherein the switch is mounted on said engine and the diaphragm is exposed to the engine oil pressure, 4and the engine oil pressure gauge and ignition system is electrically connected with the movable contact.

References Cited by the Examiner UNITED STATES PATENTS 2,418,536 4/1947 Wood 20G-83 

1. AN ENGINE OIL SENDER AND SAFETY SWITCH COMPRISING IN COMBINATION: A HOUSING HAVING A FIRST AND SECOND END AND HAVING AN INTERIOR; A FLEXIBLE DIAPHRAGM EXTENDING ACROSS THE INTERIOR OF THE HOUSING TO DIVIDE THE HOUSING INTERIOR INTO A FIRST COMPARTMENT AT THE FIRST END AND A SECOND COMPARTMENT AT THE SECOND END, SAID HOUSING BEING COMPRISED OF THREE PARTS, THE FIRST PART BEING AT THE FIRST END AND THE SECOND PART BEING AT THE SECOND END AND A CENTRAL PARTITION IN BETWEEN BOTH ENDS EXTENDING ACROSS THE HOUSING INTERIOR IN SAID SECOND COMPARTMENT; THE HOUSING FIRST END HAVING AN ADAPTER MEANS COUPLING WITH THE ENGINE AND AN OPENING COMMUNICATING WITH THE FIRST COMPARTMENT RECEIVING ENGINE OIL UNDER PRESSURE FLEXING THE DIAPHRAGM BETWEEN A FIRST POSITION AT WHICH THERE IS A PREDETERMINED LOWER PRESSURE AND A PREDETERMINED HIGHER PRESSURE; A SHAFT ANCHORED TO THE CENTER OF THE DIAPHRAGM AND EXTENDING INTO THE SECOND COMPARTMENT; SPRING MEANS BIASING SAID DIAPHRAGM TO SAID FIRST POSITION AND ADAPTED TO BE OVERCOME BY A PREDETERMINED SAFE OIL PRESSURE WHEREUPON THE DIAPHRAGM WILL BE DISPOSED IN SAID SECOND POSITION; A STATIONARY SWITCH CONTACT MOUNTED BY SAID HOUSING IN SAID SECOND COMPARTMENT; A MOVABLE SWITCH CONTACT COUPLED FOR MOVEMENT WITH THE SHAFT AWAY FROM THE STATIONARY CONTACT TO BREAK AN ELECTRICAL CONNECTION THEREBETWEEN WHEN THE DIAPHRAGM IS IN THE SECOND POSITION AND IN CONTACT WITH THE STATIONARY CONTACT TO MAKE AN ELECTRICAL CONNECTION THEREBETWEEN WHEN THE DIAPHRAGM IS IN THE FIRST POSITION, THE STATIONARY CONTACT EXTENDING INTO THE SECOND COMPARTMENT FROM SAID PARTITION AND A RECIPROCAL ARM BEING MOUNTED BY SAID PARTITION AND MOUNTING THE MOVABLE CONTACT, A BRACKET EXTENDING FROM SAID PARTITION INTO THE SECOND COMPARTMENT, THE SPRING BIASING MEANS INCLUDING A SPRING HAVING ONE END ENGAGED WITH THE BRACKET AND HAVING ANOTHER END ENGAGED WITH THE ARM TO URGE THE ARM AND, CONSEQUENTLY, THE MOVABLE SWITCH INTO ENGAGEMENT WITH THE CLOSED CONTACT, SAID SHAFT EXTENDING THROUGH AN OPENING IN SAID PARTITION AND ENGAGING THE ARM WHEN THE DIAPHRAGM IS IN SAID SECOND POSITION TO URGE THE ARM AGAINST THE BIAS OF THE SPRING AND, CONSEQUENTLY, THE MOVABLE CONTACT AWAY FROM THE STATIONARY CONTACT. 